The Apocalypto Project's Test Scans of a Bundle of Locked Model Letters

Courtesy of The Apocalpto Project. A video showing the layers of a high contrast TDI CT (Time Delay Integration, computed tomography) test scan of a bundle of 20 locked letter models. Using historic letterlocking techniques, iron gall ink, quill, and sealing wax , the #SignedSealedUndelivered team made up the batch of new letters for testing.

Imaging

The researchers are employing a range of innovative techniques to read the unopened letters – without breaking their seals. One example will include the latest advances in X-ray technology from the field of dentistry, developed by the Apocalypto group including Dr Graham Davis and Dr David Mills, at Queen Mary, University of London. Their team will read the letters for the first time without damaging this unique archive. Because early modern ink contained iron, incredibly delicate scanning can detect it on the paper. By scanning each layer of paper in a letter packet, we should be able to piece the letters back like jigsaw puzzles and read them without breaking the seals.